This was the third attack by the LoS against Gotham City. Keep in mind that the first attack created the Depression, and Ra's credited the Wayne's for saving the city. But he didn't care. Because at the top of their list is saving the world from Gotham and setting an example, not saving Gotham.

Missed this great post. This concisely sums up what I've been trying to argue for months regarding this whole scenario.

Ra's was not rational. He only seemed rational, but all of that unravels pretty quickly once you realize he is the reason Gotham is "limping along" in Begins. He never wanted Gotham to fix itself because that spits in the face of everything he believes in. He felt for the good of the world, it needed to be razed to the ground. Everything else he says is just an attempt to justify that base belief.